I just wanted to share an up to date photo of Kua. Look how great her beak is! You can see where it has really grown out. The break line used to be just below her nostrils.
She is doing really excellently today!

If anyone is searching and finds this thread ( hen or chicken with a broken beak / mandible ) and you are looking for help, I do hope it helps you. I know not everyone wants to or can take their chicken to an avian certified vet, and that's totally understandable. For those that cannot do this, you can try to make the cap/brace yourself. There is a product out there called apoxie sculpt, and it is essentially a two-part epoxy that you can work with like clay, and it sets within a few hours to be rock hard and lightweight. If you have someone to help you hold the bird, you could create a cap to allow for healing in this way. The only downside is that you might need to create it, then let it sit (off of the chicken) for a few hours until it is hard, then glue it on using a low odor superglue.